2457 Commits

Author SHA1 Message Date
Mark Brown
203f2b95a8 arm64/fpsimd: Support FEAT_FPMR
FEAT_FPMR defines a new EL0 accessible register FPMR use to configure the
FP8 related features added to the architecture at the same time. Detect
support for this register and context switch it for EL0 when present.

Due to the sharing of responsibility for saving floating point state
between the host kernel and KVM FP8 support is not yet implemented in KVM
and a stub similar to that used for SVCR is provided for FPMR in order to
avoid bisection issues. To make it easier to share host state with the
hypervisor we store FPMR as a hardened usercopy field in uw (along with
some padding).

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240306-arm64-2023-dpisa-v5-3-c568edc8ed7f@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2024-03-07 17:14:53 +00:00
Oliver Upton
4a09ddb833 Merge branch kvm-arm64/kerneldoc into kvmarm/next
* kvm-arm64/kerneldoc:
  : kerneldoc warning fixes, courtesy of Randy Dunlap
  :
  : Fixes addressing the widespread misuse of kerneldoc-style comments
  : throughout KVM/arm64.
  KVM: arm64: vgic: fix a kernel-doc warning
  KVM: arm64: vgic-its: fix kernel-doc warnings
  KVM: arm64: vgic-init: fix a kernel-doc warning
  KVM: arm64: sys_regs: fix kernel-doc warnings
  KVM: arm64: PMU: fix kernel-doc warnings
  KVM: arm64: mmu: fix a kernel-doc warning
  KVM: arm64: vhe: fix a kernel-doc warning
  KVM: arm64: hyp/aarch32: fix kernel-doc warnings
  KVM: arm64: guest: fix kernel-doc warnings
  KVM: arm64: debug: fix kernel-doc warnings

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-03-07 00:56:16 +00:00
Oliver Upton
9bd8d7df19 Merge branch kvm-arm64/vfio-normal-nc into kvmarm/next
* kvm-arm64/vfio-normal-nc:
  : Normal-NC support for vfio-pci @ stage-2, courtesy of Ankit Agrawal
  :
  : KVM's policy to date has been that any and all MMIO mapping at stage-2
  : is treated as Device-nGnRE. This is primarily done due to concerns of
  : the guest triggering uncontainable failures in the system if they manage
  : to tickle the device / memory system the wrong way, though this is
  : unnecessarily restrictive for devices that can be reasoned as 'safe'.
  :
  : Unsurprisingly, the Device-* mapping can really hurt the performance of
  : assigned devices that can handle Gathering, and can be an outright
  : correctness issue if the guest driver does unaligned accesses.
  :
  : Rather than opening the floodgates to the full ecosystem of devices that
  : can be exposed to VMs, take the conservative approach and allow PCI
  : devices to be mapped as Normal-NC since it has been determined to be
  : 'safe'.
  vfio: Convey kvm that the vfio-pci device is wc safe
  KVM: arm64: Set io memory s2 pte as normalnc for vfio pci device
  mm: Introduce new flag to indicate wc safe
  KVM: arm64: Introduce new flag for non-cacheable IO memory

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-03-07 00:56:01 +00:00
Oliver Upton
8dbc41105e Merge branch kvm-arm64/lpi-xarray into kvmarm/next
* kvm-arm64/lpi-xarray:
  : xarray-based representation of vgic LPIs
  :
  : KVM's linked-list of LPI state has proven to be a bottleneck in LPI
  : injection paths, due to lock serialization when acquiring / releasing a
  : reference on an IRQ.
  :
  : Start the tedious process of reworking KVM's LPI injection by replacing
  : the LPI linked-list with an xarray, leveraging this to allow RCU readers
  : to walk it outside of the spinlock.
  KVM: arm64: vgic: Don't acquire the lpi_list_lock in vgic_put_irq()
  KVM: arm64: vgic: Ensure the irq refcount is nonzero when taking a ref
  KVM: arm64: vgic: Rely on RCU protection in vgic_get_lpi()
  KVM: arm64: vgic: Free LPI vgic_irq structs in an RCU-safe manner
  KVM: arm64: vgic: Use atomics to count LPIs
  KVM: arm64: vgic: Get rid of the LPI linked-list
  KVM: arm64: vgic-its: Walk the LPI xarray in vgic_copy_lpi_list()
  KVM: arm64: vgic-v3: Iterate the xarray to find pending LPIs
  KVM: arm64: vgic: Use xarray to find LPI in vgic_get_lpi()
  KVM: arm64: vgic: Store LPIs in an xarray

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-03-07 00:55:53 +00:00
Oliver Upton
0d874858c6 Merge branch kvm-arm64/vm-configuration into kvmarm/next
* kvm-arm64/vm-configuration: (29 commits)
  : VM configuration enforcement, courtesy of Marc Zyngier
  :
  : Userspace has gained the ability to control the features visible
  : through the ID registers, yet KVM didn't take this into account as the
  : effective feature set when determing trap / emulation behavior. This
  : series adds:
  :
  :  - Mechanism for testing the presence of a particular CPU feature in the
  :    guest's ID registers
  :
  :  - Infrastructure for computing the effective value of VNCR-backed
  :    registers, taking into account the RES0 / RES1 bits for a particular
  :    VM configuration
  :
  :  - Implementation of 'fine-grained UNDEF' controls that shadow the FGT
  :    register definitions.
  KVM: arm64: Don't initialize idreg debugfs w/ preemption disabled
  KVM: arm64: Fail the idreg iterator if idregs aren't initialized
  KVM: arm64: Make build-time check of RES0/RES1 bits optional
  KVM: arm64: Add debugfs file for guest's ID registers
  KVM: arm64: Snapshot all non-zero RES0/RES1 sysreg fields for later checking
  KVM: arm64: Make FEAT_MOPS UNDEF if not advertised to the guest
  KVM: arm64: Make AMU sysreg UNDEF if FEAT_AMU is not advertised to the guest
  KVM: arm64: Make PIR{,E0}_EL1 UNDEF if S1PIE is not advertised to the guest
  KVM: arm64: Make TLBI OS/Range UNDEF if not advertised to the guest
  KVM: arm64: Streamline save/restore of HFG[RW]TR_EL2
  KVM: arm64: Move existing feature disabling over to FGU infrastructure
  KVM: arm64: Propagate and handle Fine-Grained UNDEF bits
  KVM: arm64: Add Fine-Grained UNDEF tracking information
  KVM: arm64: Rename __check_nv_sr_forward() to triage_sysreg_trap()
  KVM: arm64: Use the xarray as the primary sysreg/sysinsn walker
  KVM: arm64: Register AArch64 system register entries with the sysreg xarray
  KVM: arm64: Always populate the trap configuration xarray
  KVM: arm64: nv: Move system instructions to their own sys_reg_desc array
  KVM: arm64: Drop the requirement for XARRAY_MULTI
  KVM: arm64: nv: Turn encoding ranges into discrete XArray stores
  ...

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-03-07 00:51:31 +00:00
Oliver Upton
a040adfb7e Merge branch kvm-arm64/misc into kvmarm/next
* kvm-arm64/misc:
  : Miscellaneous updates
  :
  :  - Fix handling of features w/ nonzero safe values in set_id_regs
  :    selftest
  :
  :  - Cleanup the unused kern_hyp_va() asm macro
  :
  :  - Differentiate nVHE and hVHE in boot-time message
  :
  :  - Several selftests cleanups
  :
  :  - Drop bogus return value from kvm_arch_create_vm_debugfs()
  :
  :  - Make save/restore of SPE and TRBE control registers affect EL1 state
  :    in hVHE mode
  :
  :  - Typos
  KVM: arm64: Fix TRFCR_EL1/PMSCR_EL1 access in hVHE mode
  KVM: selftests: aarch64: Remove unused functions from vpmu test
  KVM: arm64: Fix typos
  KVM: Get rid of return value from kvm_arch_create_vm_debugfs()
  KVM: selftests: Print timer ctl register in ISTATUS assertion
  KVM: selftests: Fix GUEST_PRINTF() format warnings in ARM code
  KVM: arm64: removed unused kern_hyp_va asm macro
  KVM: arm64: add comments to __kern_hyp_va
  KVM: arm64: print Hyp mode
  KVM: arm64: selftests: Handle feature fields with nonzero minimum value correctly

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-03-07 00:50:23 +00:00
Marc Zyngier
9a3bfb27ef KVM: arm64: Fix TRFCR_EL1/PMSCR_EL1 access in hVHE mode
When running in hVHE mode, EL1 accesses are performed with the EL12
accessor, as we run with HCR_EL2.E2H=1.

Unfortunately, both PMSCR_EL1 and TRFCR_EL1 are used with the
EL1 accessor, meaning that we actually affect the EL2 state. Duh.

Switch to using the {read,write}_sysreg_el1() helpers that will do
the right thing in all circumstances.

Note that the 'Fixes:' tag doesn't represent the point where the bug
was introduced (there is no such point), but the first practical point
where the hVHE feature is usable.

Cc: James Clark <james.clark@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Fixes: 38cba55008e5 ("KVM: arm64: Force HCR_E2H in guest context when ARM64_KVM_HVHE is set")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240229145417.3606279-1-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-03-01 18:53:47 +00:00
Oliver Upton
5c1ebe9ada KVM: arm64: Don't initialize idreg debugfs w/ preemption disabled
Testing KVM with DEBUG_ATOMIC_SLEEP enabled doesn't get far before hitting the
first splat:

  BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1578
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 13062, name: vgic_lpi_stress
  preempt_count: 1, expected: 0
  2 locks held by vgic_lpi_stress/13062:
   #0: ffff080084553240 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0xc0/0x13f0
   #1: ffff800080485f08 (&kvm->arch.config_lock){+.+.}-{3:3}, at: kvm_arch_vcpu_ioctl+0xd60/0x1788
  CPU: 19 PID: 13062 Comm: vgic_lpi_stress Tainted: G        W  O       6.8.0-dbg-DEV #1
  Call trace:
   dump_backtrace+0xf8/0x148
   show_stack+0x20/0x38
   dump_stack_lvl+0xb4/0xf8
   dump_stack+0x18/0x40
   __might_resched+0x248/0x2a0
   __might_sleep+0x50/0x88
   down_write+0x30/0x150
   start_creating+0x90/0x1a0
   __debugfs_create_file+0x5c/0x1b0
   debugfs_create_file+0x34/0x48
   kvm_reset_sys_regs+0x120/0x1e8
   kvm_reset_vcpu+0x148/0x270
   kvm_arch_vcpu_ioctl+0xddc/0x1788
   kvm_vcpu_ioctl+0xb6c/0x13f0
   __arm64_sys_ioctl+0x98/0xd8
   invoke_syscall+0x48/0x108
   el0_svc_common+0xb4/0xf0
   do_el0_svc+0x24/0x38
   el0_svc+0x54/0x128
   el0t_64_sync_handler+0x68/0xc0
   el0t_64_sync+0x1a8/0x1b0

kvm_reset_vcpu() disables preemption as it needs to unload vCPU state
from the CPU to twiddle with it, which subsequently explodes when
taking the parent inode's rwsem while creating the idreg debugfs file.

Fix it by moving the initialization to kvm_arch_create_vm_debugfs().

Fixes: 891766581dea ("KVM: arm64: Add debugfs file for guest's ID registers")
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240227094115.1723330-3-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-27 19:19:52 +00:00
Oliver Upton
29ef55cec3 KVM: arm64: Fail the idreg iterator if idregs aren't initialized
Return an error to userspace if the VM's ID register values haven't been
initialized in preparation for changing the debugfs file initialization
order.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240227094115.1723330-2-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-27 19:19:05 +00:00
Ankit Agrawal
8c47ce3e1d KVM: arm64: Set io memory s2 pte as normalnc for vfio pci device
To provide VM with the ability to get device IO memory with NormalNC
property, map device MMIO in KVM for ARM64 at stage2 as NormalNC.
Having NormalNC S2 default puts guests in control (based on [1],
"Combining stage 1 and stage 2 memory type attributes") of device
MMIO regions memory mappings. The rules are summarized below:
([(S1) - stage1], [(S2) - stage 2])

S1           |  S2           | Result
NORMAL-WB    |  NORMAL-NC    | NORMAL-NC
NORMAL-WT    |  NORMAL-NC    | NORMAL-NC
NORMAL-NC    |  NORMAL-NC    | NORMAL-NC
DEVICE<attr> |  NORMAL-NC    | DEVICE<attr>

Still this cannot be generalized to non PCI devices such as GICv2.
There is insufficient information and uncertainity in the behavior
of non PCI driver. A driver must indicate support using the
new flag VM_ALLOW_ANY_UNCACHED.

Adapt KVM to make use of the flag VM_ALLOW_ANY_UNCACHED as indicator to
activate the S2 setting to NormalNc.

[1] section D8.5.5 of DDI0487J_a_a-profile_architecture_reference_manual.pdf

Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Ankit Agrawal <ankita@nvidia.com>
Link: https://lore.kernel.org/r/20240224150546.368-4-ankita@nvidia.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-24 17:57:39 +00:00
Ankit Agrawal
c034ec84e8 KVM: arm64: Introduce new flag for non-cacheable IO memory
Currently, KVM for ARM64 maps at stage 2 memory that is considered device
(i.e. it is not RAM) with DEVICE_nGnRE memory attributes; this setting
overrides (as per the ARM architecture [1]) any device MMIO mapping
present at stage 1, resulting in a set-up whereby a guest operating
system cannot determine device MMIO mapping memory attributes on its
own but it is always overridden by the KVM stage 2 default.

This set-up does not allow guest operating systems to select device
memory attributes independently from KVM stage-2 mappings
(refer to [1], "Combining stage 1 and stage 2 memory type attributes"),
which turns out to be an issue in that guest operating systems
(e.g. Linux) may request to map devices MMIO regions with memory
attributes that guarantee better performance (e.g. gathering
attribute - that for some devices can generate larger PCIe memory
writes TLPs) and specific operations (e.g. unaligned transactions)
such as the NormalNC memory type.

The default device stage 2 mapping was chosen in KVM for ARM64 since
it was considered safer (i.e. it would not allow guests to trigger
uncontained failures ultimately crashing the machine) but this
turned out to be asynchronous (SError) defeating the purpose.

Failures containability is a property of the platform and is independent
from the memory type used for MMIO device memory mappings.

Actually, DEVICE_nGnRE memory type is even more problematic than
Normal-NC memory type in terms of faults containability in that e.g.
aborts triggered on DEVICE_nGnRE loads cannot be made, architecturally,
synchronous (i.e. that would imply that the processor should issue at
most 1 load transaction at a time - it cannot pipeline them - otherwise
the synchronous abort semantics would break the no-speculation attribute
attached to DEVICE_XXX memory).

This means that regardless of the combined stage1+stage2 mappings a
platform is safe if and only if device transactions cannot trigger
uncontained failures and that in turn relies on platform capabilities
and the device type being assigned (i.e. PCIe AER/DPC error containment
and RAS architecture[3]); therefore the default KVM device stage 2
memory attributes play no role in making device assignment safer
for a given platform (if the platform design adheres to design
guidelines outlined in [3]) and therefore can be relaxed.

For all these reasons, relax the KVM stage 2 device memory attributes
from DEVICE_nGnRE to Normal-NC.

The NormalNC was chosen over a different Normal memory type default
at stage-2 (e.g. Normal Write-through) to avoid cache allocation/snooping.

Relaxing S2 KVM device MMIO mappings to Normal-NC is not expected to
trigger any issue on guest device reclaim use cases either (i.e. device
MMIO unmap followed by a device reset) at least for PCIe devices, in that
in PCIe a device reset is architected and carried out through PCI config
space transactions that are naturally ordered with respect to MMIO
transactions according to the PCI ordering rules.

Having Normal-NC S2 default puts guests in control (thanks to
stage1+stage2 combined memory attributes rules [1]) of device MMIO
regions memory mappings, according to the rules described in [1]
and summarized here ([(S1) - stage1], [(S2) - stage 2]):

S1           |  S2           | Result
NORMAL-WB    |  NORMAL-NC    | NORMAL-NC
NORMAL-WT    |  NORMAL-NC    | NORMAL-NC
NORMAL-NC    |  NORMAL-NC    | NORMAL-NC
DEVICE<attr> |  NORMAL-NC    | DEVICE<attr>

It is worth noting that currently, to map devices MMIO space to user
space in a device pass-through use case the VFIO framework applies memory
attributes derived from pgprot_noncached() settings applied to VMAs, which
result in device-nGnRnE memory attributes for the stage-1 VMM mappings.

This means that a userspace mapping for device MMIO space carried
out with the current VFIO framework and a guest OS mapping for the same
MMIO space may result in a mismatched alias as described in [2].

Defaulting KVM device stage-2 mappings to Normal-NC attributes does not
change anything in this respect, in that the mismatched aliases would
only affect (refer to [2] for a detailed explanation) ordering between
the userspace and GuestOS mappings resulting stream of transactions
(i.e. it does not cause loss of property for either stream of
transactions on its own), which is harmless given that the userspace
and GuestOS access to the device is carried out through independent
transactions streams.

A Normal-NC flag is not present today. So add a new kvm_pgtable_prot
(KVM_PGTABLE_PROT_NORMAL_NC) flag for it, along with its
corresponding PTE value 0x5 (0b101) determined from [1].

Lastly, adapt the stage2 PTE property setter function
(stage2_set_prot_attr) to handle the NormalNC attribute.

The entire discussion leading to this patch series may be followed through
the following links.
Link: https://lore.kernel.org/all/20230907181459.18145-3-ankita@nvidia.com
Link: https://lore.kernel.org/r/20231205033015.10044-1-ankita@nvidia.com

[1] section D8.5.5 - DDI0487J_a_a-profile_architecture_reference_manual.pdf
[2] section B2.8 - DDI0487J_a_a-profile_architecture_reference_manual.pdf
[3] sections 1.7.7.3/1.8.5.2/appendix C - DEN0029H_SBSA_7.1.pdf

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Ankit Agrawal <ankita@nvidia.com>
Link: https://lore.kernel.org/r/20240224150546.368-2-ankita@nvidia.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-24 17:57:39 +00:00
Bjorn Helgaas
75841d89f3 KVM: arm64: Fix typos
Fix typos, most reported by "codespell arch/arm64".  Only touches comments,
no code changes.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Zenghui Yu <yuzenghui@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: kvmarm@lists.linux.dev
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20240103231605.1801364-6-helgaas@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-24 09:13:33 +00:00
Oliver Upton
e27f2d561f KVM: arm64: vgic: Don't acquire the lpi_list_lock in vgic_put_irq()
The LPI xarray's xa_lock is sufficient for synchronizing writers when
freeing a given LPI. Furthermore, readers can only take a new reference
on an IRQ if it was already nonzero.

Stop taking the lpi_list_lock unnecessarily and get rid of
__vgic_put_lpi_locked().

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240221054253.3848076-11-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-23 21:46:02 +00:00
Oliver Upton
50ac89bb70 KVM: arm64: vgic: Ensure the irq refcount is nonzero when taking a ref
It will soon be possible for get() and put() calls to happen in
parallel, which means in most cases we must ensure the refcount is
nonzero when taking a new reference. Switch to using
vgic_try_get_irq_kref() where necessary, and document the few conditions
where an IRQ's refcount is guaranteed to be nonzero.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240221054253.3848076-10-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-23 21:46:02 +00:00
Oliver Upton
864d4304ec KVM: arm64: vgic: Rely on RCU protection in vgic_get_lpi()
Stop acquiring the lpi_list_lock in favor of RCU for protecting
the read-side critical section in vgic_get_lpi(). In order for this to
be safe, we also need to be careful not to take a reference on an irq
with a refcount of 0, as it is about to be freed.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240221054253.3848076-9-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-23 21:46:02 +00:00
Oliver Upton
a5c7f011cb KVM: arm64: vgic: Free LPI vgic_irq structs in an RCU-safe manner
Free the vgic_irq structs in an RCU-safe manner to allow reads of the
LPI configuration data to happen in parallel with the release of LPIs.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240221054253.3848076-8-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-23 21:46:02 +00:00
Oliver Upton
05f4d4f5d4 KVM: arm64: vgic: Use atomics to count LPIs
Switch to using atomics for LPI accounting, allowing vgic_irq references
to be dropped in parallel.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240221054253.3848076-7-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-23 21:46:02 +00:00
Oliver Upton
9880835af7 KVM: arm64: vgic: Get rid of the LPI linked-list
All readers of LPI configuration have been transitioned to use the LPI
xarray. Get rid of the linked-list altogether.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240221054253.3848076-6-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-23 21:46:02 +00:00
Oliver Upton
2798683b8c KVM: arm64: vgic-its: Walk the LPI xarray in vgic_copy_lpi_list()
Start iterating the LPI xarray in anticipation of removing the LPI
linked-list.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240221054253.3848076-5-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-23 21:46:02 +00:00
Oliver Upton
49f0a468a1 KVM: arm64: vgic-v3: Iterate the xarray to find pending LPIs
Start walking the LPI xarray to find pending LPIs in preparation for
the removal of the LPI linked-list. Note that the 'basic' iterator
is chosen here as each iteration needs to drop the xarray read lock
(RCU) as reads/writes to guest memory can potentially block.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240221054253.3848076-4-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-23 21:46:02 +00:00
Oliver Upton
5a021df719 KVM: arm64: vgic: Use xarray to find LPI in vgic_get_lpi()
Iterating over the LPI linked-list is less than ideal when the desired
index is already known. Use the INTID to index the LPI xarray instead.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240221054253.3848076-3-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-23 21:46:02 +00:00
Oliver Upton
1d6f83f60f KVM: arm64: vgic: Store LPIs in an xarray
Using a linked-list for LPIs is less than ideal as it of course requires
iterative searches to find a particular entry. An xarray is a better
data structure for this use case, as it provides faster searches and can
still handle a potentially sparse range of INTID allocations.

Start by storing LPIs in an xarray, punting usage of the xarray to a
subsequent change. The observant among you will notice that we added yet
another lock to the chain of locking order rules; document the ordering
of the xa_lock. Don't worry, we'll get rid of the lpi_list_lock one
day...

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240221054253.3848076-2-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-23 21:46:01 +00:00
Ryan Roberts
5a00bfd6a5 arm64/mm: new ptep layer to manage contig bit
Create a new layer for the in-table PTE manipulation APIs.  For now, The
existing API is prefixed with double underscore to become the arch-private
API and the public API is just a simple wrapper that calls the private
API.

The public API implementation will subsequently be used to transparently
manipulate the contiguous bit where appropriate.  But since there are
already some contig-aware users (e.g.  hugetlb, kernel mapper), we must
first ensure those users use the private API directly so that the future
contig-bit manipulations in the public API do not interfere with those
existing uses.

The following APIs are treated this way:

 - ptep_get
 - set_pte
 - set_ptes
 - pte_clear
 - ptep_get_and_clear
 - ptep_test_and_clear_young
 - ptep_clear_flush_young
 - ptep_set_wrprotect
 - ptep_set_access_flags

Link: https://lkml.kernel.org/r/20240215103205.2607016-11-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morse <james.morse@arm.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22 15:27:18 -08:00
Ryan Roberts
659e193027 arm64/mm: convert set_pte_at() to set_ptes(..., 1)
Since set_ptes() was introduced, set_pte_at() has been implemented as a
generic macro around set_ptes(..., 1).  So this change should continue to
generate the same code.  However, making this change prepares us for the
transparent contpte support.  It means we can reroute set_ptes() to
__set_ptes().  Since set_pte_at() is a generic macro, there will be no
equivalent __set_pte_at() to reroute to.

Note that a couple of calls to set_pte_at() remain in the arch code.  This
is intentional, since those call sites are acting on behalf of core-mm and
should continue to call into the public set_ptes() rather than the
arch-private __set_ptes().

Link: https://lkml.kernel.org/r/20240215103205.2607016-9-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morse <james.morse@arm.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22 15:27:18 -08:00
Marc Zyngier
99101dda29 KVM: arm64: Make build-time check of RES0/RES1 bits optional
In order to ease the transition towards a state of absolute
paranoia where all RES0/RES1 bits gets checked against what
KVM know of them, make the checks optional and guarded by a
config symbol (CONFIG_KVM_ARM64_RES_BITS_PARANOIA) default to n.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/kvm/87frxka7ud.wl-maz@kernel.org/
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-22 18:13:53 +00:00
Oliver Upton
85a71ee9a0 KVM: arm64: vgic-its: Test for valid IRQ in MOVALL handler
It is possible that an LPI mapped in a different ITS gets unmapped while
handling the MOVALL command. If that is the case, there is no state that
can be migrated to the destination. Silently ignore it and continue
migrating other LPIs.

Cc: stable@vger.kernel.org
Fixes: ff9c114394aa ("KVM: arm/arm64: GICv4: Handle MOVALL applied to a vPE")
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240221092732.4126848-3-oliver.upton@linux.dev
Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-02-21 10:06:41 +00:00
Oliver Upton
8d3a7dfb80 KVM: arm64: vgic-its: Test for valid IRQ in its_sync_lpi_pending_table()
vgic_get_irq() may not return a valid descriptor if there is no ITS that
holds a valid translation for the specified INTID. If that is the case,
it is safe to silently ignore it and continue processing the LPI pending
table.

Cc: stable@vger.kernel.org
Fixes: 33d3bc9556a7 ("KVM: arm64: vgic-its: Read initial LPI pending table")
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240221092732.4126848-2-oliver.upton@linux.dev
Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-02-21 10:06:41 +00:00
Marc Zyngier
891766581d KVM: arm64: Add debugfs file for guest's ID registers
Debugging ID register setup can be a complicated affair. Give the
kernel hacker a way to dump that state in an easy to parse way.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-27-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:02 +00:00
Marc Zyngier
b80b701d5a KVM: arm64: Snapshot all non-zero RES0/RES1 sysreg fields for later checking
As KVM now strongly relies on accurately handling the RES0/RES1 bits
on a number of paths, add a compile-time checker that will blow in
the face of the innocent bystander, should they try to sneak in an
update that changes any of these RES0/RES1 fields.

It is expected that such an update will come with the relevant
KVM update if needed.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-26-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:02 +00:00
Marc Zyngier
84de212d73 KVM: arm64: Make FEAT_MOPS UNDEF if not advertised to the guest
We unconditionally enable FEAT_MOPS, which is obviously wrong.

So let's only do that when it is advertised to the guest.
Which means we need to rely on a per-vcpu HCRX_EL2 shadow register.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20240214131827.2856277-25-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:02 +00:00
Marc Zyngier
b03e8bb5a9 KVM: arm64: Make AMU sysreg UNDEF if FEAT_AMU is not advertised to the guest
No AMU? No AMU! IF we see an AMU-related trap, let's turn it into
an UNDEF!

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-24-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:01 +00:00
Marc Zyngier
58627b722e KVM: arm64: Make PIR{,E0}_EL1 UNDEF if S1PIE is not advertised to the guest
As part of the ongoing effort to honor the guest configuration,
add the necessary checks to make PIR_EL1 and co UNDEF if not
advertised to the guest, and avoid context switching them.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20240214131827.2856277-23-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:01 +00:00
Marc Zyngier
8ecdccb9e5 KVM: arm64: Make TLBI OS/Range UNDEF if not advertised to the guest
Outer Shareable and Range TLBI instructions shouldn't be made available
to the guest if they are not advertised. Use FGU to disable those,
and set HCR_EL2.TLBIOS in the case the host doesn't have FGT. Note
that in that later case, we cannot efficiently disable TLBI Range
instructions, as this would require to trap all TLBIs.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20240214131827.2856277-22-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:01 +00:00
Marc Zyngier
d196c20c6e KVM: arm64: Streamline save/restore of HFG[RW]TR_EL2
The way we save/restore HFG[RW]TR_EL2 can now be simplified, and
the Ampere erratum hack is the only thing that still stands out.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-21-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:01 +00:00
Marc Zyngier
c5bac1ef7d KVM: arm64: Move existing feature disabling over to FGU infrastructure
We already trap a bunch of existing features for the purpose of
disabling them (MAIR2, POR, ACCDATA, SME...).

Let's move them over to our brand new FGU infrastructure.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-20-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:01 +00:00
Marc Zyngier
f5a5a406b4 KVM: arm64: Propagate and handle Fine-Grained UNDEF bits
In order to correctly honor our FGU bits, they must be converted
into a set of FGT bits. They get merged as part of the existing
FGT setting.

Similarly, the UNDEF injection phase takes place when handling
the trap.

This results in a bit of rework in the FGT macros in order to
help with the code generation, as burying per-CPU accesses in
macros results in a lot of expansion, not to mention the vcpu->kvm
access on nvhe (kern_hyp_va() is not optimisation-friendly).

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-19-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:01 +00:00
Marc Zyngier
2fd8f31c32 KVM: arm64: Add Fine-Grained UNDEF tracking information
In order to efficiently handle system register access being disabled,
and this resulting in an UNDEF exception being injected, we introduce
the (slightly dubious) concept of Fine-Grained UNDEF, modeled after
the architectural Fine-Grained Traps.

For each FGT group, we keep a 64 bit word that has the exact same
bit assignment as the corresponding FGT register, where a 1 indicates
that trapping this register should result in an UNDEF exception being
reinjected.

So far, nothing populates this information, nor sets the corresponding
trap bits.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-18-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:01 +00:00
Marc Zyngier
085eabaa74 KVM: arm64: Rename __check_nv_sr_forward() to triage_sysreg_trap()
__check_nv_sr_forward() is not specific to NV anymore, and does
a lot more. Rename it to triage_sysreg_trap(), making it plain
that its role is to handle where an exception is to be handled.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-17-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:01 +00:00
Marc Zyngier
cc5f84fbb0 KVM: arm64: Use the xarray as the primary sysreg/sysinsn walker
Since we always start sysreg/sysinsn handling by searching the
xarray, use it as the source of the index in the correct sys_reg_desc
array.

This allows some cleanup, such as moving the handling of unknown
sysregs in a single location.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-16-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:01 +00:00
Marc Zyngier
19f3e7ea29 KVM: arm64: Register AArch64 system register entries with the sysreg xarray
In order to reduce the number of lookups that we have to perform
when handling a sysreg, register each AArch64 sysreg descriptor
with the global xarray. The index of the descriptor is stored
as a 10 bit field in the data word.

Subsequent patches will retrieve and use the stored index.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-15-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:01 +00:00
Marc Zyngier
7fd498f473 KVM: arm64: Always populate the trap configuration xarray
As we are going to rely more and more on the global xarray that
contains the trap configuration, always populate it, even in the
non-NV case.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-14-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:00 +00:00
Marc Zyngier
89bc63fabc KVM: arm64: nv: Move system instructions to their own sys_reg_desc array
As NV results in a bunch of system instructions being trapped, it makes
sense to pull the system instructions into their own little array, where
they will eventually be joined by AT, TLBI and a bunch of other CMOs.

Based on an initial patch by Jintack Lim.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-13-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:00 +00:00
Marc Zyngier
52571d058b KVM: arm64: Drop the requirement for XARRAY_MULTI
Now that we don't use xa_store_range() anymore, drop the added
complexity of XARRAY_MULTI for KVM. It is likely still pulled
in by other bits of the kernel though.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-12-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:00 +00:00
Marc Zyngier
fdd8e34523 KVM: arm64: nv: Turn encoding ranges into discrete XArray stores
In order to be able to store different values for member of an
encoding range, replace xa_store_range() calls with discrete
xa_store() calls and an encoding iterator.

We end-up using a bit more memory, but we gain some flexibility
that we will make use of shortly.

Take this opportunity to tidy up the error handling path.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20240214131827.2856277-11-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:00 +00:00
Marc Zyngier
9958d58779 KVM: arm64: nv: Correctly handle negative polarity FGTs
Negative trap bits are a massive pain. They are, on the surface,
indistinguishable from RES0 bits. Do you trap? or do you ignore?

Thankfully, we now have the right infrastructure to check for RES0
bits as long as the register is backed by VNCR, which is the case
for the FGT registers.

Use that information as a discriminant when handling a trap that
is potentially caused by a FGT.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-10-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:00 +00:00
Marc Zyngier
0beb14de74 KVM: arm64: Unify HDFG[WR]TR_GROUP FGT identifiers
There is no reason to have separate FGT group identifiers for
the debug fine grain trapping. The sole requirement is to provide
the *names* so that the SR_FGF() macro can do its magic of picking
the correct bit definition.

So let's alias HDFGWTR_GROUP and HDFGRTR_GROUP.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-9-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:00 +00:00
Marc Zyngier
76b457a5cd KVM: arm64: nv: Drop sanitised_sys_reg() helper
Now that we have the infrastructure to enforce a sanitised register
value depending on the VM configuration, drop the helper that only
used the architectural RES0 value.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-8-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:00 +00:00
Marc Zyngier
d39051d392 KVM: arm64: nv: Add sanitising to VNCR-backed HCRX_EL2
Just like its little friends, HCRX_EL2 gets the feature set treatment
when backed by VNCR.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-7-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:00 +00:00
Marc Zyngier
11adda4010 KVM: arm64: nv: Add sanitising to VNCR-backed FGT sysregs
Fine Grained Traps are controlled by a whole bunch of features.
Each one of them must be checked and the corresponding masks
computed so that we don't let the guest apply traps it shouldn't
be using.

This takes care of HFG[IRW]TR_EL2, HDFG[RW]TR_EL2, and HAFGRTR_EL2.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20240214131827.2856277-6-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:00 +00:00
Marc Zyngier
81ffcace31 KVM: arm64: nv: Add sanitising to EL2 configuration registers
We can now start making use of our sanitising masks by setting them
to values that depend on the guest's configuration.

First up are VTTBR_EL2, VTCR_EL2, VMPIDR_EL2 and HCR_EL2.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-5-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:00 +00:00